#!/usr/bin/env python3

# Zulip mirror of Codebase HQ activity
# The "zulip_codebase_mirror" script is run continuously, possibly on a work
# computer or preferably on a server.
#
# When restarted, it will attempt to pick up where it left off.
#
# python-dateutil is a dependency for this script.

import requests
import logging
import pytz
import time
import sys
import os

from datetime import datetime, timedelta

try:
    import dateutil.parser
except ImportError as e:
    print(e, file=sys.stderr)
    print("Please install the python-dateutil package.", file=sys.stderr)
    exit(1)

sys.path.insert(0, os.path.dirname(__file__))
import zulip_codebase_config as config
VERSION = "0.9"

if config.ZULIP_API_PATH is not None:
    sys.path.append(config.ZULIP_API_PATH)
import zulip
from typing import Any, List, Dict, Optional

client = zulip.Client(
    email=config.ZULIP_USER,
    site=config.ZULIP_SITE,
    api_key=config.ZULIP_API_KEY,
    client="ZulipCodebase/" + VERSION)
user_agent = "Codebase To Zulip Mirroring script (zulip-devel@googlegroups.com)"

# find some form of JSON loader/dumper, with a preference order for speed.
json_implementations = ['ujson', 'cjson', 'simplejson', 'json']

while len(json_implementations):
    try:
        json = __import__(json_implementations.pop(0))
        break
    except ImportError:
        continue

def make_api_call(path: str) -> Optional[List[Dict[str, Any]]]:
    response = requests.get("https://api3.codebasehq.com/%s" % (path,),
                            auth=(config.CODEBASE_API_USERNAME, config.CODEBASE_API_KEY),
                            params={'raw': 'True'},
                            headers = {"User-Agent": user_agent,
                                       "Content-Type": "application/json",
                                       "Accept": "application/json"})
    if response.status_code == 200:
        return json.loads(response.text)

    if response.status_code >= 500:
        logging.error(str(response.status_code))
        return None
    if response.status_code == 403:
        logging.error("Bad authorization from Codebase. Please check your credentials")
        sys.exit(-1)
    else:
        logging.warn("Found non-success response status code: %s %s" % (response.status_code, response.text))
        return None

def make_url(path: str) -> str:
    return "%s/%s" % (config.CODEBASE_ROOT_URL, path)

def handle_event(event: Dict[str, Any]) -> None:
    event = event['event']
    event_type = event['type']
    actor_name = event['actor_name']

    raw_props = event.get('raw_properties', {})

    project_link = raw_props.get('project_permalink')

    subject = None
    content = None
    if event_type == 'repository_creation':
        stream = config.ZULIP_COMMITS_STREAM_NAME

        project_name = raw_props.get('name')
        project_repo_type = raw_props.get('scm_type')

        url = make_url("projects/%s" % (project_link,))
        scm = "of type %s" % (project_repo_type,) if project_repo_type else ""

        subject = "Repository %s Created" % (project_name,)
        content = "%s created a new repository %s [%s](%s)" % (actor_name, scm, project_name, url)
    elif event_type == 'push':
        stream = config.ZULIP_COMMITS_STREAM_NAME

        num_commits = raw_props.get('commits_count')
        branch = raw_props.get('ref_name')
        project = raw_props.get('project_name')
        repo_link = raw_props.get('repository_permalink')
        deleted_ref = raw_props.get('deleted_ref')
        new_ref = raw_props.get('new_ref')

        subject = "Push to %s on %s" % (branch, project)

        if deleted_ref:
            content = "%s deleted branch %s from %s" % (actor_name, branch, project)
        else:
            if new_ref:
                branch = "new branch %s" % (branch,)
            content = ("%s pushed %s commit(s) to %s in project %s:\n\n" %
                       (actor_name, num_commits, branch, project))
            for commit in raw_props.get('commits'):
                ref = commit.get('ref')
                url = make_url("projects/%s/repositories/%s/commit/%s" % (project_link, repo_link, ref))
                message = commit.get('message')
                content += "* [%s](%s): %s\n" % (ref, url, message)
    elif event_type == 'ticketing_ticket':
        stream = config.ZULIP_TICKETS_STREAM_NAME

        num = raw_props.get('number')
        name = raw_props.get('subject')
        assignee = raw_props.get('assignee')
        priority = raw_props.get('priority')
        url = make_url("projects/%s/tickets/%s" % (project_link, num))

        if assignee is None:
            assignee = "no one"
        subject = "#%s: %s" % (num, name)
        content = ("""%s created a new ticket [#%s](%s) priority **%s** assigned to %s:\n\n~~~ quote\n %s""" %
                   (actor_name, num, url, priority, assignee, name))
    elif event_type == 'ticketing_note':
        stream = config.ZULIP_TICKETS_STREAM_NAME

        num = raw_props.get('number')
        name = raw_props.get('subject')
        body = raw_props.get('content')
        changes = raw_props.get('changes')

        url = make_url("projects/%s/tickets/%s" % (project_link, num))
        subject = "#%s: %s" % (num, name)

        content = ""
        if body is not None and len(body) > 0:
            content = "%s added a comment to ticket [#%s](%s):\n\n~~~ quote\n%s\n\n" % (actor_name, num, url, body)

        if 'status_id' in changes:
            status_change = changes.get('status_id')
            content += "Status changed from **%s** to **%s**\n\n" % (status_change[0], status_change[1])
    elif event_type == 'ticketing_milestone':
        stream = config.ZULIP_TICKETS_STREAM_NAME

        name = raw_props.get('name')
        identifier = raw_props.get('identifier')
        url = make_url("projects/%s/milestone/%s" % (project_link, identifier))

        subject = name
        content = "%s created a new milestone [%s](%s)" % (actor_name, name, url)
    elif event_type == 'comment':
        stream = config.ZULIP_COMMITS_STREAM_NAME

        comment = raw_props.get('content')
        commit = raw_props.get('commit_ref')

        # If there's a commit id, it's a comment to a commit
        if commit:
            repo_link = raw_props.get('repository_permalink')

            url = make_url('projects/%s/repositories/%s/commit/%s' % (project_link, repo_link, commit))

            subject = "%s commented on %s" % (actor_name, commit)
            content = "%s commented on [%s](%s):\n\n~~~ quote\n%s" % (actor_name, commit, url, comment)
        else:
            # Otherwise, this is a Discussion item, and handle it
            subj = raw_props.get("subject")
            category = raw_props.get("category")
            comment_content = raw_props.get("content")

            subject = "Discussion: %s" % (subj,)

            if category:
                format_str = "%s started a new discussion in %s:\n\n~~~ quote\n%s\n~~~"
                content = format_str % (actor_name, category, comment_content)
            else:
                content = "%s posted:\n\n~~~ quote\n%s\n~~~" % (actor_name, comment_content)

    elif event_type == 'deployment':
        stream = config.ZULIP_COMMITS_STREAM_NAME

        start_ref = raw_props.get('start_ref')
        end_ref = raw_props.get('end_ref')
        environment = raw_props.get('environment')
        servers = raw_props.get('servers')
        repo_link = raw_props.get('repository_permalink')

        start_ref_url = make_url("projects/%s/repositories/%s/commit/%s" % (project_link, repo_link, start_ref))
        end_ref_url = make_url("projects/%s/repositories/%s/commit/%s" % (project_link, repo_link, end_ref))
        between_url = make_url("projects/%s/repositories/%s/compare/%s...%s" % (
            project_link, repo_link, start_ref, end_ref))

        subject = "Deployment to %s" % (environment,)

        content = ("%s deployed [%s](%s) [through](%s) [%s](%s) to the **%s** environment." %
                   (actor_name, start_ref, start_ref_url, between_url, end_ref, end_ref_url, environment))
        if servers is not None:
            content += "\n\nServers deployed to: %s" % (", ".join(["`%s`" % (server,) for server in servers]))

    elif event_type == 'named_tree':
        # Docs say named_tree type used for new/deleting branches and tags,
        # but experimental testing showed that they were all sent as 'push' events
        pass
    elif event_type == 'wiki_page':
        logging.warn("Wiki page notifications not yet implemented")
    elif event_type == 'sprint_creation':
        logging.warn("Sprint notifications not yet implemented")
    elif event_type == 'sprint_ended':
        logging.warn("Sprint notifications not yet implemented")
    else:
        logging.info("Unknown event type %s, ignoring!" % (event_type,))

    if subject and content:
        if len(subject) > 60:
            subject = subject[:57].rstrip() + '...'

        res = client.send_message({"type": "stream",
                                   "to": stream,
                                   "subject": subject,
                                   "content": content})
        if res['result'] == 'success':
            logging.info("Successfully sent Zulip with id: %s" % (res['id'],))
        else:
            logging.warn("Failed to send Zulip: %s %s" % (res['result'], res['msg']))


# the main run loop for this mirror script
def run_mirror() -> None:
    # we should have the right (write) permissions on the resume file, as seen
    # in check_permissions, but it may still be empty or corrupted
    def default_since() -> datetime:
        return datetime.now(tz=pytz.utc) - timedelta(hours=config.CODEBASE_INITIAL_HISTORY_HOURS)

    try:
        with open(config.RESUME_FILE) as f:
            timestamp = f.read()
        if timestamp == '':
            since = default_since()
        else:
            since = datetime.fromtimestamp(float(timestamp), tz=pytz.utc)
    except (ValueError, OSError) as e:
        logging.warn("Could not open resume file: %s" % (str(e),))
        since = default_since()

    try:
        sleepInterval = 1
        while True:
            events = make_api_call("activity")
            if events is not None:
                sleepInterval = 1
                for event in events[::-1]:
                    timestamp = event.get('event', {}).get('timestamp', '')
                    event_date = dateutil.parser.parse(timestamp)
                    if event_date > since:
                        handle_event(event)
                        since = event_date
            else:
                # back off a bit
                if sleepInterval < 22:
                    sleepInterval += 4
            time.sleep(sleepInterval)

    except KeyboardInterrupt:
        open(config.RESUME_FILE, 'w').write(since.strftime("%s"))
        logging.info("Shutting down Codebase mirror")

# void function that checks the permissions of the files this script needs.
def check_permissions() -> None:
    # check that the log file can be written
    if config.LOG_FILE:
        try:
            open(config.LOG_FILE, "w")
        except OSError as e:
            sys.stderr.write("Could not open up log for writing:")
            sys.stderr.write(str(e))
    # check that the resume file can be written (this creates if it doesn't exist)
    try:
        open(config.RESUME_FILE, "a+")
    except OSError as e:
        sys.stderr.write("Could not open up the file %s for reading and writing" % (config.RESUME_FILE,))
        sys.stderr.write(str(e))

if __name__ == "__main__":
    assert isinstance(config.RESUME_FILE, str), "RESUME_FILE path not given; refusing to continue"
    check_permissions()
    if config.LOG_FILE:
        logging.basicConfig(filename=config.LOG_FILE, level=logging.WARNING)
    else:
        logging.basicConfig(level=logging.WARNING)
    run_mirror()